Preheat oven to 425°F (220°C).
In a greased 9 x 13-inch baking dish, whisk together the broth, Alfredo sauce, garlic powder, onion powder, and Italian seasoning.
Stir in the chicken and uncooked orzo.
Cover tightly with aluminum foil and bake for 30 minutes.
Uncover; stir the orzo gently with a fork.
Check the orzo to make sure that it is al dente.
If the orzo is still too hard after 30 minutes, cover the dish again and return it to the oven until the orzo is al dente.
Stir in the spinach, lemon zest, and lemon juice.
Sprinkle the cheese over top.
Bake uncovered for about 5 more minutes (or until the cheese melts and the pasta is tender).
If you want the top crispy and brown, place it under the broiler for a minute or two.
Garnish with freshly grated Parmesan and chopped fresh herbs, if desired.
